PROJECT SUMMARY This proposal addresses a significant public health problem?parental vaccine hesitancy and refusal?for which there are currently few well-designed and rigorously evaluated interventions. National estimates of the percentage of 19 ? 35 month old children who are up-to-date on recommended vaccines remain below Healthy People 2020 goals. A key contributor to under-immunization is parental refusal or delay of vaccines due to vaccine concerns. Vaccine-hesitant parents (VHPs), a large, diverse group of parents who refuse and/or delay at least one recommended vaccine for their child, are an important population for interventions aimed at improving vaccine acceptance. While VHPs? most trusted source of information is their child?s provider, providers lack confidence in communicating with VHPs and often perceive their discussions will do little to change a parent?s mind. Improved provider communication with VHPs is therefore critical to improving childhood vaccine uptake and preventing outbreaks of vaccine-preventable disease. However, there is a lack of experimental evidence for specific communication strategies for providers. In preliminary work, Opel et al. found that provider use of a presumptive (e.g. ?Well we have to do some shots.?) rather than a participatory (e.g. ?How do you feel about vaccines today??) communication format to initiate the vaccine recommendation was associated with increased parental vaccine acceptance. This presumptive format, though, may lead to decreased parent satisfaction, raising concerns that a presumptive initiation will result in decreased vaccine uptake over time. In separate work, O?Leary et al. explored the use of Motivational Interviewing (MI) to increase uptake of HPV vaccine recommended for adolescents. Motivational Interviewing is a patient-centered framework for behavior change that contains elements that are consistent with known communication preferences of VHPs regarding vaccines. O?Leary et al. found that provider use of MI in discussions with parents who resisted the HPV vaccine recommendation resulted in increased parental vaccine acceptance and improved provider perceptions of their ability to influence parental vaccine decision-making. In this proposal, O?Leary and Opel aim to combine these two techniques?the Presumptively Initiating Vaccines and Optimizing Talk with Motivational Interviewing (PIVOT with MI) intervention?to achieve increased vaccine uptake, high parent visit satisfaction, and improved provider confidence in the vaccine conversation. Our specific aims will be to (1) develop a multifaceted, feasible, and culturally appropriate PIVOT with MI intervention provider training program; (2) evaluate the impact of the PIVOT with MI intervention on child immunization status at 19 months of age by randomizing 24 primary care practices in 2 states (Washington and Colorado) to control or intervention arms using a cluster randomized design; and (3) evaluate the impact of the PIVOT with MI intervention on parent and provider experience.